Molecular Systems Architecture of Fibrotic Lung Microenvironment in Idiopathic Pulmonary Fibrosis.

Obesity is a major and rapidly growing global health problem associated with multiple cardiometabolic and systemic comorbidities, including type 2 diabetes mellitus (T2DM), dyslipidemia, cardiovascular disease, and several cancers, ultimately reducing quality of life and life expectancy []. Worldwide, obesity prevalence nearly tripled between 1975 and 2016, affecting more than 650 million adults; in Brazil, 57.5% of adults have excess body weight, and 21.5% have obesity [,]. Body mass index (BMI) remains the most widely used measure to define obesity, stratify disease severity, and guide eligibility for bariatric surgery [,]. Although BMI does not capture body composition, fat distribution, sex, age, or ethnicity, it remains a practical and standardized measure for assessing obesity severity and monitoring postoperative anthropometric change [,]. This is particularly relevant because many bariatric studies report percentage weight loss or excess weight loss, whereas longitudinal BMI trajectories provide a direct and clinically interpretable measure aligned with diagnostic classification and surgical indication criteria. Lifestyle interventions, including dietary modification, physical activity, and behavioral strategies, are recommended as first-line therapy [,]. However, sustained weight loss remains difficult to achieve, with frequent weight regain even when combined with pharmacological treatment []. Bariatric and metabolic surgery produces greater and more durable weight loss and is associated with improvement or resolution of obesity-related comorbidities []. Roux-en-Y gastric bypass (RYGB), in particular, has been associated with substantial excess weight loss; improvements in diabetes, dyslipidemia, and hypertension []; and long-term reductions in all-cause mortality in population-based studies []. Optimal outcomes depend not only on the procedure itself, but also on appropriate patient selection, standardized surgical technique, and structured multidisciplinary follow-up [].